1. Technical Field
The invention relates to towed vehicles and particularly to a system and apparatus for deploying a decoy for protection of an aircraft, and even more particular, to such a system in which the decoy is towed by an electro-optical cable having a stationary terminus at the aircraft.
2. Background Information
Aerial towed objects are used for a variety of purposes, including decoys, testing, and scientific investigations. In one embodiment, the decoys are used to draw various types of guided weapons, such as missiles, away from an aircraft that the weapons are intended to destroy. These towed targets and decoys contain various types of electronic circuits to create an apparent target to a weapon which attracts the weapon to the decoy rather than the aircraft. One such electronic circuit has a traveling wave tube amplifier and antennas to which high voltages must be applied to power the traveling wave tube. Additionally, other controls for the traveling wave tube or other electronics in the towed object are transmitted along a fiber optic transmission line, which is both fragile and frangible.
In one type of deployment system, the decoy is simply cut loose after it has fulfilled its function. In this case, the fiber optic wires and the high tension line are severed, with the severing taking place after the high voltage has been removed and after all usable signals along the fiber optic cable have been terminated. In other types of deployment systems the decoy is retrieved by various mechanisms, such as shown in pending application Ser. No. 10/027,325, filed Dec. 20, 2001; Ser. No. 10/105,716, filed Mar. 25, 2002; and Ser. No. 10/027,352, filed Dec. 20, 2001.
By way of further background, the types of decoys involved have included devices which counter-measure infrared guided and radar guided missiles that pose the primary threats to military aircraft engaged in a combat environment. It will be appreciated that these missiles use their radar guidance systems to get within striking distance of the aircraft, thereby substantially increasing their probability that the IR system on the missile will be able to lock onto the target.
Current military aircraft are vulnerable to attack from IR-guided surface-to-air and air-to-air missiles. Statistical data on aircraft losses in hostile actions since 1980 show that almost 90 percent of these losses have been the result of IR-guided missile attacks. As a result, the ability to deploy decoys that can counter-measure both the RF and IR guidance systems on these missiles is of great value to protect aircraft during combat situations. As mentioned above, the IR-guided system initially utilizes radar guidance and then switches over to IR guidance as they come into closer proximity to the target. If one can counter-measure the radar system, then the IR portion can never lock onto the particular infrared target. To do this, the missile is deflected away by generating a signal that causes the radar guidance system in the missile to think that the target is actually elsewhere than it actually is. Furthermore, a decoy containing a laser countermeasure controlled via fiber-optic link can counter an IR missile should the radar guidance not be sufficiently interrupted.
Since these towed decoys require fiber optic wires and high tension voltages lines in order to supply the power and jamming signals to the decoys, it requires a cable capable of delivering such voltage and fiber optic signals. Heretofore, this required a fiber optic rotary joint or slip ring technology in order to transfer the signal and voltages from the source aircraft to the cable, which when deployed is unwound from a spool contained in the aircraft. This can result in problems both from the payout velocity and reliability due to its inability to perform rapid deployment to length and to the required relatively large rotary joints and high voltage slip rings required which can fail to be within the volume constraints imposed on such a system. Thus, these prior systems requiring the fiber optic and high voltage cables lack an efficient manner to provide a satisfactory connection between the cable being unwound from a reel and its stationary connection at the aircraft in a compact assembly. Thus, there is a need for a compact launching system for decoys with an improved payout system which uses an electro-optic cable with a stationary optical terminus at the aircraft eliminating the heretofore used rotary joint or slip ring technology.
Some prior art decoys are sacrificed and the towline cable is cut at the aircraft at the end of flight or mission. Thus, these systems do not require the winching in or reeling in of the decoy after deployment and passing of a missile attack. This enables the decoys to be rapidly deployed. One rapid deployment system includes a spindle that pays out the towline in much the same way as a spinning reel pays out a fishing line. Although spinning reel-like techniques have existed for fishing, in the area of rapidly deployed decoys they were not used to winch decoys.
U.S. Pat. Nos. 5,836,535; 5,603,470; 5,605,306; 5,570,854; 5,501,411; 5,333,814; 5,094,405; 5,102,063; 5,136,295; 4,808,999; 4,978,086; 5,029,773; 5,020,742; 3,987,746; and 5,014,997 cover in general, other types of towed vehicle deployment all incorporated herein by reference. In none of these patents is the use of a stationary optical terminus shown or taught as that of the present invention.